Nonlinear Model Order Reduction

The MAMBA model order reduction is capable of preserving the nonlinear behavior stemming from the contact interfaces of jointed structures.

While the contact interfaces introduce local nonlinearities into a jointed structure the components of the jointed structure can still be assumed as linear elastic. Therefore it is possible to utilize the superposition principle to describe the total deformation of the involved components.

A reduction basis constructed according to Craig and Bampton ensures very good result quality in case of linear elastic structures. This is achieved by the so called constrained modes, which represent static displacement shapes, and boundary fixed normal modes, which represent the internal dynamics of the linear elastic structure.

In case of jointed structures it is also essential that the reduction basis is capable to accurately capture the local displacements due to the occurring contact stresses. This is achieved by an additional set of trial vectors. These so called joint interface or contact modes are formulated to reproduce the local deformations due to the contact stresses. As the structure is capable to deform in a physical meaningful way the computed contact stresses are meaningful as well.